Sony CMD-Z5 - Manual (Page 22)

22 GB
Memo during a call
You can record the conversation for up to 20 seconds. Also, you can play
back the pre-recorded Voice memos, to let the caller hear them, during
conversation.
Pressing
records a Voice memo. To playback a memo, open Memo
from the Main Menu. Then open the Voice memo box and select the memo
you want to playback for the caller.
Important
Obtain permission from the other party beforehand if you want to record the
conversation. Also, be aware that the recorded contents can be listened to by third
parties if they have access to your phone.